Direct and correlated responses to two-stage selection for ovulation rate and number of fully formed pigs at birth in swine.

Direct and correlated responses to two-stage selection for ovulation rate and number of fully formed pigs at birth in swine.

Our objectives were to estimate responses and genetic parameters for ovulation rate, number of fully formed pigs at birth, and other production traits following two-stage selection for increased ovulation rate and number of fully formed pigs. Eight generations of selection were practiced in each of two lines. One selection line was derived from a line that previously selected eight generations ...

Selection for ovulation rate in rabbits: direct and correlated responses estimated with a cryopreserved control population.

The aim of this work was to evaluate the response in 10 generations of selection for ovulation rate in rabbits using a cryopreserved control population. Selection was based on the phenotypic value of ovulation rate estimated at d 12 of second gestation by laparoscopy. To produce the control population, embryos from 50 donor females and 18 males, belonging to the base generation of the line sele...

Two-stage Selection for Ovulation Rate and Litter Size in Swine â•fl An Effective Procedure to Increase Reproductive Rate

Selection for ovulation rate in swine: correlated response in litter size and weight.

Nine generations of direct selection for ovulation rate (OR) were evaluated to determine the magnitude of the correlated response in three litter size and two litter weight traits. A total of 387 Select line and 394 Control line litters were included in the ten generations of data. Realized heritabili ty of OR was .42 -+ .06 based on the regression of response (SelectControl) on weighted cumula...

Direct responses to selection for increased litter size, decreased age at puberty, or random selection following selection for ovulation rate in swine.

Nine generations of selection for high ovulation rate were followed by two generations of random selection and then eight generations of selection for increased litter size at birth, decreased age at puberty, or continued random selection in the high ovulation rate line. A control line was maintained with random selection. Line means were regressed on generation number and on cumulative selecti...